What is the main idea of the selection?
A
Many people were surprised when Obama won his first small election contest in early 2008.
B
Hillary Clinton and the other Democratic Party's candidates did not think Obama had a chance of winning.
C
Barack Obama got millions of people to volunteer to work for him after he became president.
D
President Obama and his supporters worked hard to get him elected when others thought it was impossible.
D
President Obama and his supporters worked hard to get him elected when others thought it was impossible.